//201902104030_何琛选
package cn.edu.sdjzu.xg.bysj.controller.basic;

import cn.edu.sdjzu.xg.bysj.domain.GraduateProjectType;
import cn.edu.sdjzu.xg.bysj.service.GraduateProjectTypeService;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.serializer.SerializerFeature;
import lombok.extern.slf4j.Slf4j;
import util.Condition;
import util.ControllerHelper;
import util.JSONUtil;
import util.Pagination;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.sql.SQLException;
import java.util.Collection;
import java.util.List;

@Slf4j
@WebServlet("/graduateProjectType.ctl")
public class GraduateProjectTypeController extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //设置请求字符编码为UTF-8
        request.setCharacterEncoding("UTF-8");
        //根据request对象，获得代表参数的JSON字串
        String gra_json = JSONUtil.getJSON(request);
        //将JSON字串解析为School对象
        GraduateProjectType graToAdd = JSON.parseObject
                (gra_json, GraduateProjectType.class);
        //设置响应字符编码为UTF-8
        response.setContentType("text/html;charset=UTF-8");
        //创建JSON对象message，以便往前端响应信息
        JSONObject message = new JSONObject();
        //在数据库表中增加School对象
        try {
            GraduateProjectTypeService.getInstance().add(graToAdd);
            message.put("message", "增加成功");
        }catch (SQLException e){
            message.put("message", "数据库操作异常");
        }catch(Exception e){
            message.put("message", e);
        }
        //响应message到前端
        response.getWriter().println(message);
    }

    /**
     * DELETE, http://localhost:8080/school.ctl?id=1, 删除id=1的学院
     * 删除一个学院对象：根据来自前端请求的id，删除数据库表中id的对应记录
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doDelete(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //读取参数id
        String id_str = request.getParameter("id");

        //创建JSON对象message，以便往前端响应信息
        JSONObject message = new JSONObject();

        try {
            if (id_str == null){//根据School对象删除
                String gra_json = JSONUtil.getJSON(request);

                GraduateProjectType graToDelete =
                        JSON.parseObject(gra_json, GraduateProjectType.class);

                if(GraduateProjectTypeService.getInstance().delete(graToDelete,null)) {
                    message.put("message", "删除成功");
                }else
                    message.put("message", "删除失败");
            }else {//根据id删除
                int id = Integer.parseInt(id_str);
                GraduateProjectTypeService.getInstance().delete(id);
                message.put("message", "删除成功");
            }

        }catch (SQLException e){
            message.put("message", "数据库操作异常");
        }catch(Exception e){
            message.put("message", "网络异常");
        }
        //响应message到前端
        response.getWriter().println(message);
    }

    /**
     * PUT, http://localhost:8080/school.ctl, 修改学院
     *
     * 修改一个学院对象：将来自前端请求的JSON对象，更新数据库表中相同id的记录
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doPut(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //设置请求字符编码为UTF-8
        request.setCharacterEncoding("UTF-8");
        //根据request对象，获得代表参数的JSON字串
        String gra_json = JSONUtil.getJSON(request);
        //将JSON字串解析为School对象
        GraduateProjectType graToUpdate = JSON.parseObject(gra_json, GraduateProjectType.class);

        //设置响应字符编码为UTF-8
        response.setContentType("text/html;charset=UTF-8");
        //创建JSON对象message，以便往前端响应信息
        JSONObject message = new JSONObject();
        //到数据库表修改School对象对应的记录
        try {
            GraduateProjectTypeService.getInstance().update(graToUpdate);
            message.put("message", "修改成功");
        }catch (SQLException e){
            message.put("message", "数据库操作异常");
        }catch(Exception e){
            message.put("message", "网络异常");
        }
        //响应message到前端
        response.getWriter().println(message);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //创建JSON对象respMessage_jsonObj，以便往前端响应信息
        JSONObject respMessage_jsonObj = new JSONObject();

        //将request body转换为JSON字串
        String req_jsonStr = JSONUtil.getJSON(request);
        //将request body解析为JSONObject对象
        JSONObject req_jsonObj = JSON.parseObject(req_jsonStr);
        //如果请求body为空
        if (req_jsonObj == null) {
            respMessage_jsonObj.put("message","未收到请求信息！");
            response.getWriter().println(respMessage_jsonObj);
            return;
        }
        //从JSONObject对象中读取键“id”的值（Java Object对象），req_jsonObj可能是{"id":1}
        Object id_obj = req_jsonObj.get("id");
        try {
            //如果id_Obj != null, 说明请求数据有id键，是请求某个学院对象
            if (id_obj != null) {
                int id_int = Integer.parseInt(id_obj.toString());
                responseGraduateProjectType(id_int, response);
            } else {//请求中包含条件和分页信息，需要响应多个学院对象
                //读取分页信息，形成分页对象
                //从JSONObject对象中读取 “pagination” 键对应的值(JSONObject对象)
                Pagination pagination = ControllerHelper.getPagination(req_jsonObj);
                //从请求JSONObject对象中读取键“conditionList”对应的值(描述查询条件的JSONArray对象)
                List<Condition> conditionList = ControllerHelper.getConditions(req_jsonObj);
                //响应多个学院信息，其中conditionList, pagination两个对象引用为空是可能的
                this.responseGraduateProjectTypes(response, conditionList, pagination);
            }
        } catch (SQLException e) {
            respMessage_jsonObj.put("message", "数据库操作异常");
            //响应respMessage_jsonObj到前端
            response.getWriter().println(respMessage_jsonObj);
            //打印异常栈，方便调试（要用log4j代替）
            log.info(e.getMessage());
        } catch (Exception e) {
            respMessage_jsonObj.put("message", "网络异常");
            //响应respMessage_jsonObj到前端
            response.getWriter().println(respMessage_jsonObj);
            //打印异常栈，方便调试（要用log4j代替）
            log.info(e.getMessage());
        }
    }

    //响应一个GraduateProjectType对象
    private void responseGraduateProjectType(int id, HttpServletResponse response)
            throws ServletException, IOException, SQLException {
        //根据id查找GraduateProjectType
        GraduateProjectType graduateProjectType = GraduateProjectTypeService.getInstance().find(id);
        String graduateProjectType_json = JSON.toJSONString(graduateProjectType);

        //响应graduateProjectType_json到前端
        response.getWriter().println(graduateProjectType_json);
    }
    //响应所有GraduateProjectType对象
    private void responseGraduateProjectTypes(HttpServletResponse response,
                                              List<Condition>conditionList_json_str,
                                              Pagination pagination)
            throws ServletException, IOException, SQLException {
        //获得所有GraduateProjectType
        Collection<GraduateProjectType> graduateProjectTypes =
                GraduateProjectTypeService.getInstance().
                        findAll(conditionList_json_str, pagination);
        String graduateProjectTypes_json = JSON.toJSONString(graduateProjectTypes, SerializerFeature.DisableCircularReferenceDetect);

        //响应graduateProjectTypes_json到前端
        response.getWriter().println(graduateProjectTypes_json);
    }

}
